Devices for signalling the passage of moving objects



p 1967 M. J. WARD 3,341,703

DEVICES FOR SIGNALLING THE PASSAGE OF MOVING OBJECTS Filed May 1'7, 1965 2 Sheets-Sheet 1 m m a Q R Q a) 1 1 (i I} I! i Q s; g u Q f o 1 o Lj/m g 52 L05; I v &

Inventor A ttorneys M. J. WARD Sept. 12, 1967 DEVICES FOR SIGNALLING THE PASSAGE OF MOVING OBJECTS Filed May 17, 1965 2 Sheets-Sheet 2:

w u vgzt'w United States Patent 3,341,703 DEVICES FOR SIGNALLING THE PASSAGE 0F MOVING OBJECTS Montague James Ward, London, England, assignor to Corsemarts Electrical Engineers Limited, Basildon, England Filed May 17, 1965, Ser. No. 456,103 8 Claims. (Cl. 246247) ABSTRACT OF THE DISCLOSURE A device for counting the number in a series of objects of substantial weight passing in rapid succession, including a member displaceable in two directions and cooperating switch means, the latter being operated to register a count in response to simultaneously occurring displacement of the member in both directions, the one due to drive imparted to the displaceable member by frictional contact of an object as it passes and the other due to the weight of the object bearing on the displaceable member, the displaceable member being a resiliently deformable rotary member with switching to indicate a count resulting from the rotation of said member and simultaneous axial movement of at least a portion thereof under the effect of substantially radial squeezing.

This invention relates to devices for signalling the passage of moving objects. More particularly, it is concerned with indicating the number of train wheels passing a given point along a railway track.

Over many years considerable effort has been expended with the view to devising a completely reliable indication of a trains position along a given track, as is required in any system of automatic train control. The signalling devices developed have, however, been prone to failure primarily due to short circuiting of electrical apparatus by rain, ice, snow and so forth, but also as a result of accidental or malicious interference. A further serious disadvantage of prior devices is that they either cannot give confirmation that a train passing out of a section of track is still complete, or can only be made to do so at the penalty of very considerably complication which is undesirable both from economic considerations and because it increases the failure risk. It will be understood that it is not enough for the equipment to signal the entry of a train into a track section and then to signal departure of a train at the other end of the station. If a train should part while in the section it could be duly signalled out and still leave the section behind it obstructed.

An attractive possibility is actually to count the wheels of a train as it passes. Then if the same count is obtained when a train enters a section and when it leaves, it is sill intact. Furthermore, if the counting can be achieved by mechanical coaction between the wheels and the counting device the prime cause of failure associated with electrical equipments is eliminated. The problem is to provide a robust mechanical device that will count reliably at high speed, which is not prone to give spurious counts and which is. virtually proof against inadvertent or malicious operation. It is an object of this invention to achieve object as it passes and the other due to the weight of the object bearing on the displaceable member.

The displaceable member may be a resiliently deformable rotary member, wi-th switching to indicate a count resulting from rotation of said member and simultaneous axial movement of at least a portion thereof under the effect of substantially radial squeezing. Specifically, in the case of a rail-mounted device for counting train Wheels, the deformable member may comprise an elastomeric roll to be mounted at the inside of the rail with its axis substantially horizontal and its top surface at a level below the top of the rail such that the roll is deformed by squashing under the weight as a wheel flange rolls over it.

According to another aspect of the invention, a device for counting the wheels of a passing train comprises a displaceable member and cooperating switch contacts responding to displacements of said member, the displaceable member being disposed alongside a rail on the inside thereof at a position where it is enaged by the portion of the flange of a passing wheel which is for the time being below the top of the rail. Thereby the displaceable member is given a comparatively slow and limited impulsion in the direction opposite to that in which the train is travelling. Since the part of the flange below the rail is only turning slowly the device is operated by comparatively slow movements even although the train be travelling at high speed, and therefore a high count rate is possible.

One form of construction in accordance with the invention will now be described by way of example, reference being had to the accompanying drawings in which:

FIGURE 1 shows a signalling device according to the invention in longitudinal cross section,

FIGURE 2 is a view of parts of the device as seen looking on the line 22 of FIGURE 1, and

FIGURE 3 is an end view of the device seen in the direction of the arrow 3 of FIGURE 1.

The signalling device to be described has a frame or housing 11 which can be mounted by means of a clamp 12 on a rail 13. The clamp 12 comprises a pair of jaws 14 to engage one edge of the bottom flange of the rail, and a single centre jaw 15 to engage the opposite edge. The jaws 14 have lower legs 16 that project under the rail flange and are united at their extremities by a cross piece 17 to form a yoke. The jaw 15 is carried by a separate member 18 that is connected by bolts 19 to the cross piece 17, the bolts serving the tighten the jaws 14, 15 on the rail flange. Each of the jaws 14 has integral with the upper leg thereof a thick pad of metal forming a pedestal 20.

The housing 11 comprises a main section 21, a forward section 22 bolted to the front end of the main section, and an end bell 23 bolted to the back of the main section. The forward section 22 is mainly annular but has integral side arms 24 extending toward the rail 13 and terminating in bosses 25. These bosses overlie the pedestals 20 on the clamp jaws 14 and are secured thereto by long vertical bolts 26 extending down through the bosses into threaded bores in the pedestals. Shims 27 on the bolt shanks are interposed between the bosses 25 and the pedestals 20, thereby providing a means of adjustment of the housing in the vertical plane relative to the rail 13. Limited horizontal adjustment is provided by making one of the bores in the bosses 25 somewhat oval with the major axis substantially at right angles to the direction of length of the rail. The main section 21 of the housing has a screwed socket 28 in its top portion for attachment of a carrying handle 29.

At their sides nearest the rail the bosses 25 have flats 30 to which are bolted the two ends of a horizontal 3 bridge member 31. The bridge member has a central hole in which is received one end of a dead shaft 32. The other end of the dead shaft 32 is received in a socket 33 in the end bell 23. Around the dead shaft 32 is a hollow rotary shaft 34 which runs at its forward end on lands 35 on the dead shaft while its rear end is supported in a ball bearing 36 that is in turn mounted in the main section of the housing 11. The outer race of the ball bearing is clamped between a shoulder in the main section of the housing and the end bell 23. The rotary shaft 34 is prevented from axial movement in the direction toward the rail 13 by a nut 37 and lock washer 38 on a threaded extremity of the shaft projecting at the rear of the ball bearing 36. j

Immediately in front of the ball bearing 36, and abutting the inner race thereof, is a rotary clutch member 39 which is keyed to the shaft by a bell 40 that cooperates with a. slot 41 so as not to prevent axial movement. In front of the rotary .clutch member 39 is a clutch member 42 that is loose on the shaft 34, and then comes a further clutch member 43 that is keyed to rotate with the shaft by a ball 44, this ball also cooperating with a slot '45 so as to permit axial movement of the clutch member 43.

'The clutch member 43 is urged axially away from the The back face of the roll 48 has bonded to it an annular plate 49; this is also coned but in the opposite direction to the flange 47 so that the plate 49 and flange 47 diverge as their peripheries are approached. The back of the plate 49 bears on a forward-facing shoulder of the clutch member 43.

A spring switch arm 50 carries a switch contact 51 to cooperate with a fixed contact 52. The contacts are normally held closed by a pivoted switch-actuating member 53 acting on the arm 50 but if the clutch member 43 slides axially away from the rail 13 a sufficient distance it encounters a tail 54 on the switch-actuating member 53 and causes the switch contacts to open.

A further switch comprises a resilient switch arm 53 carrying a moving contact 56 that lies between spaced fixed contacts 57, 58. This switch is operated by a cam 1ift59 on the periphery of the central clutch member 42. The clutch member has a radial peg 60 engaged in a hole in a spring strip 61 which lies along an arc of the clutch member periphery and has its ends formed into spring spirals 62 anchored to the housing 11. By this arrangement the clutch member 42 is resiliently urged into a particular neutral angular position, i.e. the position shown in FIGURE 2. When the clutch member 42 is in the neutral position a button 63 on the switch arm 55 engages a step 64 at one end of the cam lift 59 and the switch contact 56 lies midway between the two fixed contacts 57, 58.

If the clutch member 42 is turned clockwise from the position shown in FIGURE 2 the switch arm button 63 rises on to the cam lift 59 and contacts 56, 57 are closed. If the clutch member is turned anticlockwise the switch arm button descends on to the unraised periphery of the clutch member and contacts 56, 58 are closed.

When the device is in the correct position on the inside of a rail, as shown in FIGURE 1, the flange of any passing wheel of a rail vehicle will squeeze down on the deformable roll 48. This causes the roll to extend axially and shift the clutch member 43 endwise, thereby engaging the three clutch members 39, 42, 43 and also opening the switch 51, 52. At the same time the flange imparts a comparatively slow rotational impulse to the roll, in the opposite direction to that in which the train is travelling,

and since the clutch is now engaged the cam lift 59 moves angularly in one direction or the other and closes either direction of travel of the train. However, a count in the form of an electrical pulse cannot yet be transmittedby the device because the switch 51, 52, which is now open, is in series with both the switch 56, 57 and the switch 56, 58. Not until the wheel flange is moving off the roll and the latter is returning to its normal shape does the switch 51, 52 reclose, as the clutch member 43 returns to its initial position, enabling the electrical circuit to transmit a count pulse. By this means the occurrence of a false count, should a wheel stop directly over the roll and then run back slightly before going on, is prevented.

A device as described will count at a rate of 25 to 30 times per second, equivalent to trains travelling at to miles per hour, without missing a count. Moreover since the device is clamped directly to the rail it is insensitive to rail bounce.

The lightest wheel load that will run over such a mechanism is more than six tons. Consequently, if the device is arranged to require that magnitude of load to operate it the possibilityof inadvertent. or malicious operation can be ignored.

By reason of the provisions for adjustment already de scribed, the elastomeric roll can be set at an appropriate position in relation to the top of the rail and it will be seen in FIGURE 1 of the drawings that the roll is of ample extent in its axial direction to accommodate the possible lateral movement of the wheel flanges. The elastomeric material will normally be a synthetic plastic, such as polyurethane, of a hard-wearing character rather than rubber. Or it may be advantageous to employ a composite roll with a plastic outer layer bonded onto a rubber core.

I claim:

1. A device for counting the number in a series of objects of substantial weight passing in rapid succession, comprising a member displaceable in two directions and cooperating switch means, the switch means being operated to register a count in response to simultaneously occurring displacement of said member in both directions the one due to drive imparted to the displaceable member by frictional contact of an object as it passes and the other due to the weight of the object bearing on the displaceable member, and characterised in that the displaceable memher is aresiliently deformable rotary member and switching to indicate a count results from the rotation of said member and simultaneous axial movement of at least a portion thereof under the effect of substantially radial squeezing.

2. A device according to claim 1, wherein the objects to be counted are train wheels, said deformable member being disposed alongside a rail in a position where it is engaged by the wheel flanges.

3. A device according to claim 2, wherein the deformable member comprises an elastomeric roll to .be mounted at the inside of the rail with its axis substantially horizontal and its top surface at a level below the top of the rail such that the roll is deformed by squashing under the weight as a wheel flange rolls over it.

4. A device according to claim 3, and comprising at least one switch actuated by the rotary motion andat least one other switch actuated by the axial movement, these two switches being connected in series, and wherein the axial-movement-actuated switch is arranged to be opened when axial movement due to squeezing of the roll by a wheel flange takes place and recloses when the squeezing pressure is released, whereby the circuit through the two switches is not completed until the flange has passed substantially right over and off the roll.

5. A device according to claim 1 comprising a normally disengaged clutch which is engaged by the axial movement thereby enabling the rotary motionrto be imparted to angularly movable switch-actuating means.

PIi1 for each direction of angular movement from neutral whereby the device is sensitive to the direction in which the objects are passing.

7. A device for counting the Wheels of a passing train and comprising a displaceable member and cooperating switch contacts responding to displacements of said member, the displaceable member being disposed alongside a rail on the inside thereof at a position Where it is engaged by the portion of the flange of a passing wheel which is for the time being below the top of the rail, whereby the displaceable member is given a comparatively slow 10 and limited impulsion in the direction opposite to that in which the train is travelling, characterized in that the displaceable member is a deformable rotary roll of elastomeric material to which a frictional drive is imparted by the periphery of the wheel flange, the flange simultaneously squeezing down on the roll and thereby causing it to displace axially.

8. A device according to claim 7, adapted to be clamped to the rail so as to partake of any movements thereof.

References Cited UNITED STATES PATENTS 1,100,957 6/1914 Davis 246246 1,329,773 2/1920 Karl 246246 1,879,070 9/1932 Burke 246246 X 1,999,823 4/1935 Obergfell et al. 246246 2,083,288 6/1937 Bone 246246 2,108,497 2/ 1938 Livingston 246246 2,847,562 8/1958 Marquardt 24677 X 15 ARTHUR L. LA POINT, Primary Examiner.

S. B. GREEN, Assistant Examiner. 

1. A DEVICE FOR COUNTING THE NUMBER IN A SERIES OF OBJECTS OF SUBSTANTIAL WEIGHT PASSING IN RAPID SUCCESSION, COMPRISING A MEMBER DISPLACEABLE IN TWO DIRECTIONS AND COOPERATING SWITCH MEANS, THE SWITCH MEANS BEING OPERATED TO REGISTER A COUNT IN RESPONSE TO SIMULTANEOUSLY OCCURRING DISPLACEMENT OF SAID MEMBER IN BOTH DIRECTIONS THE ONE DUE TO DRIVE IMPARTED TO THE DISPLACEABLE MEMBER BY FRICTIONAL CONTACT OF AN OBJECT AS IT PASSES AND THE OTHER DUE TO THE WEIGHT OF THE OBJECT BEARING ON THE DISPLACEABLE MEMBER, AND CHARACTERISED IN THAT THE DISPLACEABLE MEMBER IS A RESILIENTLY DEFORMABLE ROTARY MEMBER AND SWITCHING TO INDICATE A COUNT RESULTS FROM THE ROTATION OF SAID MEMBER AND SIMULTANEOUS AXIAL MOVEMENT OF AT LEAST A PORTION THEREOF UNDER THE EFFECT OF SUBSTANTIALLY RADIAL SQUEEZING. 